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Meloni, D., Morisi, S., & Peinado, E. (2011). Neutrino phenomenology and stable dark matter with A(4). Phys. Lett. B, 697(4), 339–342.
Abstract: We present a model based on the A(4) non-Abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta(23) similar to pi/4for very small reactor angle and deviation from maximal atmospheric mixing for large theta(13). Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be vertical bar m(ee)vertical bar > 4 x 10(-4) eV.
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Meloni, D., Morisi, S., & Peinado, E. (2011). Stability of dark matter from the D(4) x Z(2)(f) flavor group. Phys. Lett. B, 703(3), 281–287.
Abstract: We study a model based on the dihedral group D(4) in which the dark matter is stabilized by the interplay between a remnant Z(2) symmetry, of the same spontaneously broken non-abelian group, and an auxiliary Z(2)(f) introduced to eliminate unwanted couplings in the scalar potential. In the lepton sector the model is compatible with normal hierarchy only and predicts a vanishing reactor mixing angle, theta(13) = 0. Since m(nu 1) = 0, we also have a simple prediction for the effective mass in terms of the solar angle: vertical bar m(beta beta)vertical bar = vertical bar m(nu 2)vertical bar sin(2)theta circle dot similar to 10(-3) eV. There also exists a large portion of the model parameter space where the upper bounds on lepton flavor violating processes are not violated. We incorporate quarks in the same scheme finding that a description of the CKM mixing matrix is possible and that semileptonic K and D decays mediated by flavor changing neutral currents are under control.
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Mathieu, V., & Vento, V. (2010). eta-eta ' mixing in the flavor basis and large N. Phys. Lett. B, 688(4-5), 314–318.
Abstract: The mass matrix for eta-eta' is derived in the flavor basis at O(p(4)) of the chiral Lagrangian using the large N approximation. Under certain assumptions, the mixing angle phi = 41.4 degrees and the decay constants ratio f(K)/f(pi) = 1.15 are calculated in agreement with the data. It appears that the FKS scheme arises as a special limit of the chiral Lagrangian. Their mass matrix is obtained without the hypothesis on the mixing pattern of the decay constants.
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Martinez Torres, A., Khemchandani, K. P., Navarra, F. S., Nielsen, M., & Oset, E. (2013). The role of f(0)(1710) in the phi omega threshold peak of J/Psi -> gamma phi omega. Phys. Lett. B, 719(4-5), 388–393.
Abstract: We study the process J/Psi -> gamma phi omega, measured by the BES experiment, where a neat peak close to the phi omega threshold is observed and is associated to a scalar meson resonance around 1800 MeV. We make the observation that a scalar resonance coupling to phi omega unavoidably couples strongly to K (K) over bar, but no trace of a peak is seen in the K (K) over bar spectrum of the J/Psi -> gamma K (K) over bar at this energy. This serves us to rule out the interpretation of the observed peak as a signal of a new resonance. After this is done, a thorough study is performed on the production of a pair of vector mesons and how its interaction leads necessarily to a peak in the J/Psi -> gamma phi omega reaction close to the phi omega threshold, due to the dynamical generation of the f(0)(1710) resonance by the vector-vector interaction. We then show that both the shape obtained for the phi omega mass distribution, as well as the strength are naturally reproduced by this mechanism. The work also explains why the phi omega peak is observed in the BES experiment and not in other reactions, like B-+/- -> K-+/-phi omega of Belle.
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Mantovani Sarti, V., & Vento, V. (2014). The half-skyrmion phase in a chiral-quark model. Phys. Lett. B, 728, 323–327.
Abstract: The Chiral Dilaton Model, where baryons arise as non-topological solitons built from the interaction of quarks and chiral mesons, shows in the high density low temperature regime a two phase scenario in the nuclear matter phase diagram. Dense soliton matter described by the Wigner-Seitz approximation generates a periodic potential in terms of the sigma and pion fields that leads to the formation of a band structure. The analysis up to three times nuclear matter density shows that soliton matter undergoes two separate phase transitions: a delocalization of the baryon number density leading to B = 1/2 structures, as in skyrmion matter, at moderate densities, and quark deconfinement at larger densities. This description fits well into the so-called quarkyonic phase where, before deconfinement, nuclear matter should undergo structural changes involving the restoration of fundamental symmetries of QCD.
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Mangano, G., Miele, G., Pastor, S., Pisanti, O., & Sarikas, S. (2012). Updated BBN bounds on the cosmological lepton asymmetry for non-zero theta(13). Phys. Lett. B, 708(1-2), 1–5.
Abstract: We discuss the bounds on the cosmological lepton number from Big Bang Nucleosynthesis (BBN), in light of recent evidences for a large value of the neutrino mixing angle theta(13), sin(2) theta(13) greater than or similar to 0.01 at 2 sigma. The largest asymmetries for electron and mu, tau neutrinos compatible with He-4 and H-2 primordial yields are computed versus the neutrino mass hierarchy and mixing angles. The flavour oscillation dynamics is traced till the beginning of BBN and neutrino distributions after decoupling are numerically computed. The latter contains in general, non-thermal distortion due to the onset of flavour oscillations driven by solar squared mass difference in the temperature range where neutrino scatterings become inefficient to enforce thermodynamical equilibrium. Depending on the value of theta(13), this translates into a larger value for the effective number of neutrinos, N-eff. Upper bounds on this parameter are discussed for both neutrino mass hierarchies. Values for N-eff which are large enough to be detectable by the Planck experiment are found only for the (presently disfavoured) range sin(2) theta(13) <= 0.01.
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Mandal, S., Srivastava, R., & Valle, J. W. F. (2021). The simplest scoto-seesaw model: WIMP dark matter phenomenology and Higgs vacuum stability. Phys. Lett. B, 819, 136458–14pp.
Abstract: We analyze the consistency of electroweak breaking, neutrino and dark matter phenomenology within the simplest scoto-seesaw model. By adding the minimal dark sector to the simplest “missing partner” type-I seesaw one has a physical picture for the neutrino oscillation lengths: the “atmospheric” mass scale arises from the tree-level seesaw, while the “solar” scale is induced radiatively, mediated by the dark sector. We identify parameter regions consistent with theoretical constraints, as well as dark matter relic abundance and direct detection searches. Using two-loop renormalization group equations we explore the stability of the vacuum and the consistency of the underlying dark parity symmetry. One also has a lower bound for the neutrinoless double beta decay amplitude.
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Mandal, S., Rojas, N., Srivastava, R., & Valle, J. W. F. (2021). Dark matter as the origin of neutrino mass in the inverse seesaw mechanism. Phys. Lett. B, 821, 136609–15pp.
Abstract: We propose that neutrino masses are “seeded” by a dark sector within the inverse seesaw mechanism. This way we have a new, “hidden”, variant of the scotogenic scenario for radiative neutrino masses. We discuss both explicit and dynamical lepton number violation. In addition to invisible Higgs decays with majoron emission, we discuss in detail the pheneomenolgy of dark matter, as well as the novel features associated to charged lepton flavour violation, and neutrino physics.
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Mandal, S., Miranda, O. G., Sanchez Garcia, G., Valle, J. W. F., & Xu, X. J. (2022). High-energy colliders as a probe of neutrino properties. Phys. Lett. B, 829, 137110–5pp.
Abstract: The mediators of neutrino mass generation can provide a probe of neutrino properties at the next round of high-energy hadron (FCC-hh) and lepton colliders (FCC-ee/ILC/CEPC/CLIC). We show how the decays of the Higgs triplet scalars mediating the simplest seesaw mechanism can shed light on the neutrino mass scale and mass-ordering, as well as the atmospheric octant. Four-lepton signatures at the high-energy frontier may provide the discovery-site for charged lepton flavor non-conservation in nature, rather than low-energy intensity frontier experiments.
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Makarenko, A. N., Odintsov, S. D., & Olmo, G. J. (2014). Little Rip, Lambda CDM and singular dark energy cosmology from Born-Infeld-f(R) gravity. Phys. Lett. B, 734, 36–40.
Abstract: We study late-time cosmic accelerating dynamics from Born-Infeld-f(R) gravity in a simplified conformal approach. We find that a variety of cosmic effects such as Little Rip, Lambda CDM universe and dark energy cosmology with finite time future singularities may occur. Unlike the convenient Born-Infeld gravity where in the absence of matter only de Sitter expansion may emerge, apparently any FRW cosmology may be reconstructed from this conformal version of the Born-Infeld-f(R) theory. Despite the fact that the explicit form of f(R) is fixed by the conformal ansatz, the relation between the two metrics in this approach may be changed so as to bring out any desired FRW cosmology.
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